The Little Missouri River, flood plain and surrounding badlands in the North Unit of Theodore Roosevelt National Park. Leafless gray trees on the flood plain are mostly cottonwood, and dark green trees are rocky mountain juniper. Cottonwood stands occur in arc-shaped bands increasing in age with distance from the channel.
Jonathan M Friedman, PhD
Jonathan Friedman is a Hydrologist at the Fort Collins Science Center.
Since joining the Fort Collins Science Center in 1993, Jonathan has devoted his career to studying interactions among riparian vegetation, river flow and channel change. Present research topics include use of riparian tree rings to reconstruct past river flow, and determination of the effect of riparian vegetation on bank stability.
Science and Products
Reconstructing Flow History From Riparian Tree Rings
FORT aquatic scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. We then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. We also use downscaled climate projections and...
Fort Collins Science Center Labs and Facilities
The Fort Collins Science Center has scientists working in several diverse locations as well as three in house highly specialized laboratories, studying subjects from molecular ecology to brown treesnakes, dendroecology to streamflows, and macroinvertebrate species to Burmese pythons. Our extraordinary scientists work in each of these locations advancing studies in their particluar areas of study...
Ecological Drought in Riparian Ecosystems
Drought is killing riparian trees along many rivers in the western United States. The cause can be increasing temperature or decreasing precipitation, flow or water-table elevation. At multiple locations we are relating water availability to physiological measurements of tree survival and water stress, such as ring width, carbon stable isotope ratio and branch hydraulic conductivity. These...
Erosion and Invasive Saltcedar
Formation of arroyos in the late 1800s greatly increased erosion across the southwestern United States. Since the 1930s, however, this erosion has decreased, partly because of bank stabilization by introduced saltcedar. With Isleta Pueblo Indian Nation, the Aquatic Systems Branch developed a new sediment dating method using saltcedar tree rings. We applied the method in a landmark study of arroyo...
Riparian Ecology
Riparian ecologists at the Fort Collins Science Center study interactions among flow, channel change, and vegetation along rivers across the western United States and worldwide. Our work focuses on issues relevant to the management of water and public lands, including dam operation, climate change, invasive species, and ecological restoration. Investigations take place on a range of scales. For...
Ecological Flows
Ecological flow is a central theme of AS Branch studies, as our research examines how water flows affect populations, communities, ecosystems, and hydroscapes. Our studies elucidate the interactions among hydrologic, geomorphologic, biogeochemical, biological, and anthropogenic processes. Branch scientists identify and quantify the spatial and temporal attributes of water flow for ecological needs...
Model-Based Scenario Planning to Inform Climate Change Adaptation in the Northern Great Plains
One of the biggest challenges facing resource managers today is not knowing exactly when, where, and how climate change effects will unfold. While models can be used to predict the types of impacts that climate change might have on a landscape, uncertainty remains surrounding factors such as how quickly changes will occur and how specific resources will respond. In order to plan for this...
Understanding the Links Between Climate, Ecosystem Processes, Wetland Management, and Bird Communities in the Prairie Pothole Region of the Northern Great Plains
In semi-arid regions, riparian and wetland ecosystems function as important migratory and breeding habitats and add significantly to local and regional biodiversity; however, these ecosystems are increasingly threatened by climate change and the potential synergistic effects of increasing demand for water and invasion by exotic species. As a continuation of our inaugural USGS National...
The Little Missouri River, flood plain
The Little Missouri River, flood plain and surrounding badlands in the North Unit of Theodore Roosevelt National Park. Leafless gray trees on the flood plain are mostly cottonwood, and dark green trees are rocky mountain juniper. Cottonwood stands occur in arc-shaped bands increasing in age with distance from the channel.
Tree ring dating
Tamarisk stem cross-section cut 2.8 m below the ground surface showing how sediment deposition is dated using tree rings. Following initial burial of 68 cm in 1969, ring-width decreased, vessel size increased, and annual transitions became less distinct. After a second burial by 41 cm in 1972, annual transitions became indistinguishable.
Tamarisk stem cross-section cut 2.8 m below the ground surface showing how sediment deposition is dated using tree rings. Following initial burial of 68 cm in 1969, ring-width decreased, vessel size increased, and annual transitions became less distinct. After a second burial by 41 cm in 1972, annual transitions became indistinguishable.
Science and Products
Reconstructing Flow History From Riparian Tree Rings
FORT aquatic scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. We then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. We also use downscaled climate projections and...
Fort Collins Science Center Labs and Facilities
The Fort Collins Science Center has scientists working in several diverse locations as well as three in house highly specialized laboratories, studying subjects from molecular ecology to brown treesnakes, dendroecology to streamflows, and macroinvertebrate species to Burmese pythons. Our extraordinary scientists work in each of these locations advancing studies in their particluar areas of study...
Ecological Drought in Riparian Ecosystems
Drought is killing riparian trees along many rivers in the western United States. The cause can be increasing temperature or decreasing precipitation, flow or water-table elevation. At multiple locations we are relating water availability to physiological measurements of tree survival and water stress, such as ring width, carbon stable isotope ratio and branch hydraulic conductivity. These...
Erosion and Invasive Saltcedar
Formation of arroyos in the late 1800s greatly increased erosion across the southwestern United States. Since the 1930s, however, this erosion has decreased, partly because of bank stabilization by introduced saltcedar. With Isleta Pueblo Indian Nation, the Aquatic Systems Branch developed a new sediment dating method using saltcedar tree rings. We applied the method in a landmark study of arroyo...
Riparian Ecology
Riparian ecologists at the Fort Collins Science Center study interactions among flow, channel change, and vegetation along rivers across the western United States and worldwide. Our work focuses on issues relevant to the management of water and public lands, including dam operation, climate change, invasive species, and ecological restoration. Investigations take place on a range of scales. For...
Ecological Flows
Ecological flow is a central theme of AS Branch studies, as our research examines how water flows affect populations, communities, ecosystems, and hydroscapes. Our studies elucidate the interactions among hydrologic, geomorphologic, biogeochemical, biological, and anthropogenic processes. Branch scientists identify and quantify the spatial and temporal attributes of water flow for ecological needs...
Model-Based Scenario Planning to Inform Climate Change Adaptation in the Northern Great Plains
One of the biggest challenges facing resource managers today is not knowing exactly when, where, and how climate change effects will unfold. While models can be used to predict the types of impacts that climate change might have on a landscape, uncertainty remains surrounding factors such as how quickly changes will occur and how specific resources will respond. In order to plan for this...
Understanding the Links Between Climate, Ecosystem Processes, Wetland Management, and Bird Communities in the Prairie Pothole Region of the Northern Great Plains
In semi-arid regions, riparian and wetland ecosystems function as important migratory and breeding habitats and add significantly to local and regional biodiversity; however, these ecosystems are increasingly threatened by climate change and the potential synergistic effects of increasing demand for water and invasion by exotic species. As a continuation of our inaugural USGS National...
The Little Missouri River, flood plain
The Little Missouri River, flood plain and surrounding badlands in the North Unit of Theodore Roosevelt National Park. Leafless gray trees on the flood plain are mostly cottonwood, and dark green trees are rocky mountain juniper. Cottonwood stands occur in arc-shaped bands increasing in age with distance from the channel.
The Little Missouri River, flood plain and surrounding badlands in the North Unit of Theodore Roosevelt National Park. Leafless gray trees on the flood plain are mostly cottonwood, and dark green trees are rocky mountain juniper. Cottonwood stands occur in arc-shaped bands increasing in age with distance from the channel.
Tree ring dating
Tamarisk stem cross-section cut 2.8 m below the ground surface showing how sediment deposition is dated using tree rings. Following initial burial of 68 cm in 1969, ring-width decreased, vessel size increased, and annual transitions became less distinct. After a second burial by 41 cm in 1972, annual transitions became indistinguishable.
Tamarisk stem cross-section cut 2.8 m below the ground surface showing how sediment deposition is dated using tree rings. Following initial burial of 68 cm in 1969, ring-width decreased, vessel size increased, and annual transitions became less distinct. After a second burial by 41 cm in 1972, annual transitions became indistinguishable.
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government